fix: add setup-python before pip install in QEMU workflow

Author: srpatcha

.github/workflows/qemu-test.yml

@@ -22,6 +22,10 @@ jobs:
             gcc-aarch64-linux-gnu gcc-arm-linux-gnueabihf \
             gcc-riscv64-linux-gnu cpio
 
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+
       - name: Install and test ebuild
         run: |
           python3 -m pip install --upgrade pip